Infrared sensors are used onboard orbiting platforms (e.g., satellites) for a variety of applications. These sensors must be periodically calibrated. This is especially important when the sensors are used onboard platforms scheduled for long deployment. Currently, an onboard calibrated reference emission source must be provided and used for sensor calibration. The reference emission source must be a stable source and/or requires monitoring. Further, stable optical path(s) used by these sensors to view the reference emission source must be provided. The reference emission system must be calibrated on the ground and then mounted to withstand the severe launch stresses it will experience and in a way that allows it to exhibit the same performance in orbit as during its ground calibration.